A fixed granular-bed sorber for measurement and control of alkali vapors in PFBC (pressurized fluidized-bed combustion)
Alkali vapors (Na and K) in the hot flue gas from the pressurized fluidized-bed combustion (PFBC) of coal could cause corrosion problems with the gas turbine blades. In a laboratory-scale PFBC test with Beulah lignite, a fixed granular bed of activated bauxite sorbent was used to demonstrate its capability for measuring and controlling alkali vapors in the PFBC flue gas. The Beulah lignite was combusted in a bed of Tymochtee dolomite at bed temperatures ranging from 850 to 875{degrees}C and a system pressure of 9.2 atm absolute. The time-averaged concentration of sodium vapor in the PFBC flue gas was determined from the analysis of two identical beds of activated bauxite and found to be 1.42 and 1.50 ppmW. The potassium vapor concentration was determined to be 0.10 ppmW. The sodium material balance showed that only 0.24% of the total sodium in the lignite was released as vapor species in the PFBC flue gas. This results in an average of 1.56 ppmW alkali vapors in the PFBC flue gas. This average is more than 1.5 orders of magnitude greater than the currently suggested alkali specification limit of 0.024 ppm for an industrial gas turbine. The adsorption data obtained with the activated bauxite beds were also analyzed mathematically by use of a LUB (length of unused bed)/equilibrium section concept. Analytical results showed that the length of the bed, L{sub o} in centimeters, relates to the break through time, {theta}{sub b} in hours, for the alkali vapor to break through the bed as follows: L{sub o} = 33.02 + 1.99 {theta}{sub b}. This formula provides useful information for the engineering design of fixed-bed activated bauxite sorbers for the measurement and control of alkali vapors in PFBC flue gas. 26 refs., 4 figs., 4 tabs.
- Research Organization:
- Argonne National Lab., IL (USA)
- Sponsoring Organization:
- DOE/FE
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 6154760
- Report Number(s):
- ANL/CP-71607; CONF-910424-1; ON: DE91004439
- Resource Relation:
- Conference: 11. international conference on fluidized bed combustion, Montreal (Canada), 21-24 Apr 1991
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measurement of alkali vapors in PFBC flue gas and their removal with a fixed granular-bed sorber, October 1, 1985-September 30, 1986
Measurement of alkali vapors in PFBC flue gas and their control by a granular-bed sorber
Related Subjects
FLUIDIZED-BED COMBUSTORS
GRANULAR BED FILTERS
PERFORMANCE
POTASSIUM
ADSORPTION
SODIUM
BAUXITE
CHEMICAL PROPERTIES
CLEANING
COAL-FIRED GAS TURBINES
CORROSION
DIMENSIONS
DOLOMITE
EROSION
EXHAUST GASES
FLOWSHEETS
FLUIDIZED-BED COMBUSTION
LIGNITE
MATERIAL BALANCE
MATHEMATICAL MODELS
PRESSURIZATION
REMOVAL
SORPTIVE PROPERTIES
TIME DEPENDENCE
TURBINE BLADES
VAPORS
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM ORES
BROWN COAL
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATE MINERALS
CARBONATES
CHEMICAL REACTIONS
COAL
COMBUSTION
COMBUSTORS
DIAGRAMS
ELEMENTS
ENERGY SOURCES
FILTERS
FLUIDS
FOSSIL FUELS
FUELS
GAS TURBINES
GASEOUS WASTES
GASES
MACHINERY
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MATERIALS
MECHANICAL FILTERS
METALS
MINERALS
ORES
OXIDATION
OXYGEN COMPOUNDS
SORPTION
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
TURBINES
TURBOMACHINERY
WASTES
010402* - Coal
Lignite
& Peat- Purification & Upgrading